1. Field of the Invention
This invention relates to a duplex (two-sided) image forming apparatus, which can selectively perform single-sided or double-sided image forming.
2. Description of Related Art
Duplex image forming is desirable in many situations in order to minimize the amount of recording media used. That is, as compared to single-sided image forming, the amount of used recording media can be cut in half because information is recorded on both sides thereof.
Several types of duplex copying apparatuses are known. In a typical duplex copying machine, conventional one-sided copying is first effected on the recording medium by a recording section, and then the recording medium is inverted and fed back through the recording section to effect the conventional one-sided copying on the reverse side.
However, duplex copiers of this type must be made sufficiently large to accommodate one or more paper supply cassettes as well as a refeeder section for holding the recording media, having been recorded on one side, to be refed to the image forming section.
Moreover, copying machines that are dedicated to single-sided copying are difficult to retrofit to enable double-sided recording.